Current calibration of geosynchronous (GEO) satellites is typically done on the earth's surface/ground, for example by terrestrial receivers (deployed on the ground within transmission footprint of the GEO satellite) that are used to measure GEO satellite signal parameters (e.g., strength and quality) as received from the being calibrated GEO satellite. In some cases, receivers are mounted on vehicles to provide a geographical measurement of the power. However, current calibration methods suffer from uncertainties caused by, for example, varying atmospheric conditions in a medium between the calibrated GEO satellite and the receivers. For example, fading due to rain in the area where the transmission footprint is measured causes uncertainties in the received power, and it may be hard to tell whether the fading is due to environmental conditions or degrading in the satellite's performance. In many cases measurement of transmission performance of a satellite is hard to be carried out for, example when the transmission footprint is on an undeveloped area with uneasy access. The present invention provides an accurate and easy to perform method and system for calibrating in-orbit satellites (such as GEO satellite), which is free of such disadvantages.
Other difficulties arise from the need to find a suitable test range on ground (hundreds of kilometers between possible measurement locations).